Field of the Invention
The present invention relates to a post-processing apparatus connected to an image forming apparatus, a post-processing method, and an image forming system.
Description of the Related Art
In a prior image forming system such as a copying machine, a post-processing apparatus for executing post-processing such as a punching process, a stapling process and a sorting process on a sheet conveyed from the image forming apparatus. US2007/047996 (A1) describes a post-processing apparatus which executes, for a sheet conveyed from an image forming apparatus, the punching process at an area near the tip of the sheet in a sheet conveying direction. In the punching process, it may be necessary to change a size and a form of a punch hole and the number of the same.
Therefore, in the post-processing apparatus, by preparing a plurality of punch dies having different numbers and/or different forms of punch holes, a currently used punch die may be replaced with another punch die as required for accommodating changing of the size of the punch holes etc. Further, providing a post-processing apparatus with a function other than a punching, for example, providing a crease die for creasing the sheet, is also proposed.
In a case where various functions are added to the post-processing apparatus, it is also necessary to change hardware and/or software configuration of the image forming apparatus for activating the added functions. Therefore, the quantity of work in developing the image forming apparatus and the post-processing apparatus may be increased. Moreover, the launch day of a new model of the image forming apparatus may be delayed due to the work for additional function. Under the above circumstance, a method of changing the configuration of hardware and/or software accompanied with the added function only in the post-processing apparatus and eliminating need for changing the configuration in the image forming apparatus is known.
As a method for causing the additional function to be activated by the post-processing apparatus only, a method for switching activation/inactivation of the function in the post-processing apparatus independent of the control of the image forming apparatus. In this method, even in a case where a new function is added to the post-processing apparatus, it is possible to activate a new function without need for receiving a notice for executing a new function from the image forming apparatus.
In this method, since it is not necessary to change the configuration of the image forming apparatus, it is possible to build a system easily by combining an existing image forming apparatus and the post-processing apparatus in which a new function is added. In the following description, an image forming system is explained. It is noted that the image forming system includes an image forming apparatus which controls the punching process and the post-processing apparatus which includes a punch die for executing the punching process.
In the post-processing apparatus of the image forming system, a crease function may be added by enabling exchanging of the punch die for executing the punching process with the crease die for executing the creasing process. In this case, a switch for activating/inactivating the post-processing is formed in the post-processing apparatus for allowing the post-processing apparatus to activate/inactivate the post-processing function independently. Therefore, when the punch die is installed in the post-processing apparatus, the punching process is performed, and when the crease die is installed, the creasing process is executed.
A user can select one of the punching process and the creasing process by exchanging the punch die and the crease die as desired. When the punching process is required, the user activates the post-processing by activating the post-processing using an exchange switch with the punch die being installed in the post-processing apparatus.
However, even in a case where the user does not wish to execute the punching process and thus the user does not cause the image forming apparatus to notify the punching process to the post-processing apparatus, the punching process is executed when the punching function is activated in the post-processing apparatus. This is due to a fact that the post-processing apparatus determines activation/inactivation of the post-processing function independent of the image forming apparatus.
It is noted that, before adding the crease function, the user can determine whether the punching process should be executed or not by using the image forming apparatus. However, after the addition of the function, the punching process may be executed against the user's will. Thus, there remains a problem that when the function is activated by the switch of the post-processing apparatus, even if a notification for the punching process is not notified from the image forming apparatus, the punching process is performed.